1. Technical Field
The present invention relates to a machining condition estimating apparatus for estimating a machining condition for suppressing wear of a tool in machining on a curved surface with applying a multi-axial work machine, and a machining condition estimating method for the same.
2. Background Art
A background technology of the present technical field is already known in Japanese Patent Laid-Open No. 2008-221454, for example. In this publication is described “to provide a method for estimating wear of a tool, so as to enable to estimate an amount of wear of the tool at high accuracy before machining, from a low-speed cutting region to a high-speed cutting region. Since the amount of wear of the tool is estimated from an estimation equation having a term for showing an influence to abrasive wear due to a hard inclusion within a material to be cut (hereinafter, “cutting material”) and a term for showing an influence to thermal diffusion wear due to the hard inclusion within the cutting material, then it is possible to estimate the amount of wear of the tool, by taking the abrasive wear, which generates mainly in the low-speed cutting region or a middle-speed cutting region, and also the thermal diffusion wear, which generates mainly the high-speed cutting region, into the consideration thereof” (see Abstract). According to the Patent Document mentioned above, it is possible to estimate the amount of wear of the tool, by collecting data necessary to an equation 3 of the Patent Document mentioned above, and to estimate a machining condition for enabling suppression of the wear of the tool.
Also, in recent years, accompanying with development of the work machines and data collecting equipment, a detecting apparatus is invented for conducting determination of a life-time of the tool under the condition of cutting work, with conducting real-time observation of a machining load from working current of a main shaft of the work machine, etc., which can be obtained from the work machine during the time of cutting work. An example of this is already known in Japanese Patent Laid-Open No. 2011-230206. In this publication is described “to provide a tool life-time detecting method for enabling to detect reaching to the life-time of the tool at high accuracy, and also a tool life-time detecting apparatus. With applying numerical information relating to a specific cutting force, which is measured in advance upon a work piece to be machined this time, and numerical information relating to a machining load value and a specific cutting force corresponding to this, which were already measured on a work piece being machined before that, a machining load value is calculated as an estimated load value, which can be estimated to generate when machining a work piece to be machined this time, and this estimated load value is compared with a reference load value to be a reference for determination of the life-time of the tool, so that it is detected that the tool mentioned above reaches to the life-time when the estimated load value mentioned above exceeds that reference load value.” In Patent Document of the latter is described a method of calculating a threshold value for a value of a main shaft of the work machine, which can be estimated when the tool reaches to the life-time thereof, in advance, and comparing the load value of the main shaft, which is detected in an actual machining, to the threshold value mentioned above; thereby detecting that the tool reaches to the life-time thereof when it exceeds the threshold value mentioned above.